# UNS C67300 Leaded Manganese Bronze

C67300 bronze is a brass formulated for primary forming into wrought products. Cited properties are appropriate for the H50 (extruded and drawn) temper.

It has a moderately low melting temperature among wrought brasses. In addition, it has a moderately low thermal conductivity and a moderately high tensile strength.

The graph bars on the material properties cards below compare C67300 bronze to: wrought brasses (top), all copper alloys (middle), and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.

## Mechanical Properties

Elastic (Young's, Tensile) Modulus

110 *GPa* 15 *x 10 ^{6} psi*

Elongation at Break

12 *%*

Poisson's Ratio

0.31

Rockwell B Hardness

91

Shear Modulus

41 *GPa* 5.9 *x 10 ^{6} psi*

Shear Strength

300 *MPa* 44 *x 10 ^{3} psi*

Tensile Strength: Ultimate (UTS)

500 *MPa* 73 *x 10 ^{3} psi*

Tensile Strength: Yield (Proof)

340 *MPa* 50 *x 10 ^{3} psi*

## Thermal Properties

Latent Heat of Fusion

190 *J/g*

Maximum Temperature: Mechanical

130 *°C* 260 *°F*

Melting Completion (Liquidus)

870 *°C* 1610 *°F*

Melting Onset (Solidus)

830 *°C* 1530 *°F*

Specific Heat Capacity

390 *J/kg-K* 0.093 *BTU/lb-°F*

Thermal Conductivity

95 *W/m-K* 55 *BTU/h-ft-°F*

Thermal Expansion

20 *µm/m-K*

## Electrical Properties

Electrical Conductivity: Equal Volume

22 *% IACS*

Electrical Conductivity: Equal Weight (Specific)

25 *% IACS*

## Otherwise Unclassified Properties

Base Metal Price

23 *% relative*

Density

8.0 *g/cm ^{3}* 500

*lb/ft*

^{3}Embodied Carbon

2.7 *kg CO _{2}/kg material*

Embodied Energy

46 *MJ/kg* 20 *x 10 ^{3} BTU/lb*

Embodied Water

320 *L/kg* 38 *gal/lb*

## Common Calculations

Resilience: Ultimate (Unit Rupture Work)

55 *MJ/m ^{3}*

Resilience: Unit (Modulus of Resilience)

550 *kJ/m ^{3}*

Stiffness to Weight: Axial

7.4 *points*

Stiffness to Weight: Bending

20 *points*

Strength to Weight: Axial

17 *points*

Strength to Weight: Bending

17 *points*

Thermal Diffusivity

30 *mm ^{2}/s*

Thermal Shock Resistance

16 *points*

## Alloy Composition

Among wrought copper alloys, the composition of C67300 bronze is notable for including aluminum (Al) and silicon (Si). Aluminum is used to add strength and oxidation resistance. Silicon is used to increase strength at the expense of ductility. It also lowers the melting temperature and raises the fluidity of the alloy.

Cu | 58 to 63 | |

Zn | 27.2 to 39.1 | |

Mn | 2.0 to 3.5 | |

Pb | 0.4 to 3.0 | |

Si | 0.5 to 1.5 | |

Fe | 0 to 0.5 | |

Sn | 0 to 0.3 | |

Ni | 0 to 0.25 | |

Al | 0 to 0.25 | |

res. | 0 to 0.5 |

All values are % weight. Ranges represent what is permitted under applicable standards.